After learning about the bigger risk of contracting a more serious strain of dengue fever for people who received a vaccine from the pharmaceutical company Sanofi last year, the Philippines Department of Health has decided to suspend the in-school program that saw the vaccination of more than 740,000 school age children.
The French pharmaceutical company responsible for creating the vaccine, Dengvaxia, released a statement on Wednesday that included data from a six year study showing that people who received the treatment, but who had not previously had dengue fever, were at an increased risk of having “more cases of severe disease” in the long term.
“For those not previously infected by dengue virus, however, the analysis found that in the longer term, more cases of severe disease could occur following vaccination upon a subsequent dengue infection,” the statement read.
Individuals who had contracted the mosquito-borne disease before receiving the shot, however, were still shown to have protection for reinfection in the future.
Dengvaxia was introduced to the Philippines market last year under a somewhat controversial move by the department of health, as health officials in the country had warned that there hadn’t been enough research into the vaccines possible side effects.
Of the children who received the vaccine, there are about 70,000 – with the youngest recipients being at least 9 – who have never had a documented case of dengue fever in their lifetime and are in this at-risk pool of children for contracting a more severe strain in the long term.
Dengue fever is one of the most widespread diseases contracted through mosquito bites and worldwide there are about 400 million cases documented each year.
Though most people will make a full recovery from the virus, there are 25,000 people each year that will die from hemorrhagic fevers brought on by the virus. These fevers often occur after having contracted the disease for the first time.
The Philippine health secretary, Francisco Duque III, told the New York Times that the program would be “on hold while review consultation are on the way”.
This will include a mandatory history survey on those who received the vaccination, a reporting of all future hospitalisations from those who received the vaccine and five years of post-vaccination follow-up.
There is expected to be more information released on the 12 or 13 December as to whether or not the program will start again, the health secretary added.
Within the Philippines, there are 200,000 cases of new infections of dengue fever reported each year. Of those who received the vaccine, most reside in regions of the country where the disease is known to be endemic.